Turbine meters are steadily improving. These basically simple, multi-bladed, measuring devices have steadily gained in acceptance by industry.
Turbine meters have been used to measure fluid as it fills a reservoir a predetermined amount. Turbine meters have been used to measure fluid as the fluid is withdrawn from the reservoir inventory. To the non-inventive mind, a meter is required to measure the fluid flow in each direction of the same path. Economics demand only one meter be used for measuring the fluid flow in both directions of a single flow path. Further, convenience and time demand the bi-directional flow be differentially measured, i.e. the single registration of volume be that of the inventory of the reservoir. These demands must be met by invention over the prior art.
Next, consider closely the meter mechanism which must be used in solving the problem. A multi-bladed rotor has its shaft parallel with the fluid flow. The blades radiate from the shaft and are at an angle to the flow to develop a force which rotates the blades and shaft.
Electro-magnetic pick-up units are positioned about the periphery of the blades. The magnetic lines of force generated by these pick-up units are cut by each rotating blade to generate an electrical pulse. The number of pulses generated within a predetermined time span establishes the rate of fluid flow through the meter.
The prior art provides a single well in the meter casing in which a single pick-up unit is mounted. Can the single, conventional pick-up well be utilized to mount more than one pick-up unit as needed to provide signals which will establish the one of two directions fluid flows through the meter? Can a plurality of pick-up units be mounted at the periphery of the blades to establish which direction fluid flows through the meter and add or subtract from a single registration to manifest the inventory supplied through the meter? These two questions underline the problems solved by the present invention.